Tool sharpener



1941- A. a. MAWLE 2,251,849

TOOL SHARPENER Filed May 2, 1940 j I H IHI JJ Patented Aug. 5, 1941UNITED STTES 4. Claims.

This invention relates to a tool sharpening device.

More particularly, the invention relates to a device for sharpeningtools and having special adaptation to the sharpening of the blades ofshears, scissors and the like.

As is generally known, the cooperating edges of the opposed blades ofshears and scissors are slightly bevelled to provide maximum cuttingefficiency and in the re-sharpening of such blades it is essential thatthe original bevels be maintained if the cutting efiiciency is to beretained.

The sharpening of the blades of shears and scissors has heretofore beendone by various means ranging from a file to more or less efiicientdevices for supporting or guiding the blades during the sharpeningoperation.

While the blades may be properly sharpened by the use of a file, it isvery difficult to secure a uniform bevel from one end to the other ofthe blades. This is likewise true if a rotary stone or the like, beused, wherein the blades are manually guided and which requires muchcare and skill to secure a uniform bevel.

Furthermore, devices have heretofore been proposed which include anabrading surface and restricted guide means for a scissors blade wherebythe blade may be manually reciprocated thereby moving the edgelengthwise over the abrading surface for the sharpening thereof.

A device of this general character is disclosed in the British PatentNo. 172,450, December 15, 1921. Wherein the guide is relatively shortand as the slot between the walls forming such guide is of necessitysubstantially wide to accommodate the wider backs of the blades, itwould require considerable care and skill to so reciprocate the blade asto secure a uniform bevel on the cutting edge thereof. Furthermore, suchdevice leaves the major portion of the blade exposed as a result ofwhich ones fingers may be cut during the sharpening operation.

A primary object of this invention is the provision of a sharpeningdevice which substantially overcomes the above noted objections, andwhich is endowed with the maximum requirements of devices of thischaracter.

A further object of the invention is the provision of a device forsharpening the blades of shears, scissors and the like embodying meansfor fully concealing the edges of the blades and maintaning same infixed position throughout the lengths thereof during the sharpeningoperation.

A still further object of the invention is the provision of a devicewhich is highly simple in construction and which is capable of beingreadily dis-assembled for repair or replacement of parts.

For a more complete understanding of the objects and nature of theinvention, reference will be had to the following detailed description,taken in connection with the accompanying drawing, wherein- Figure 1 isa top plan view of the device, constructed in accordance with apreferred embodiment of the invention.

Figure 2 is a longitudinal vertical section in a plane substantially asrepresented by the line 2-2 in Figure 1.

Figure 3 is a left hand end elevation of the device.

Figure 4 is a transverse section in a plane represented by line 44 inFigure 2.

Figure 5 is a right hand end elevation of the device.

Figure 6 is a side elevational view, on .a reduced scale, showing a pairof shears or scissors in sharpening position in the device.

Referring now in detail to the drawing by the use of referencecharacters, and wherein like characters designate like parts in thedifferent views, D designates the device in its entirety and which inits elemental construction comprises a casing ID which is preferablycylindrical in form as illustrated, but which may well be of other formsso far as the essence of the invention is concerned.

The casing 50 may be of wood, metal, or a composition material and maybe of any preferred length and diameter. The length however, should beat least equal to the length of the blades of the larger shears orscissors for reasons which will later appear.

The casing It! is provided with a bore ll in which is rotatably mounteda cylinder or roller [2, the bore l I being of slightly greater diameterthan that of the roller l2 to provide for free rotation of the latter.

The roller [2 may be mounted and actuated in various ways butpreferably, and as shown, the roller is supported on a spindle i3 whichis preferably force fitted in an axial aperture in the roller for jointrotation of the roller and spindle.

The spindle l3 at one end thereof (the left in Figures 1 and 2) projectsfreely through an. aperture in an end plate [4. The spindle adjacent itsopposite end projects freely through an aperture in another end platel5, the spindle adjacent the exterior of the plate [5 being bent atright angles and radially extended to provide a roller operating crank I6 having a suitable handle l1 freely rotatable thereon.

Th end plates l4 and I are preferably secured to the casing ID as byscrews I8 for ready removal thereof whereupon the roller l2 togetherwith the spindle l3 can readily be removed from within the casing boreH.

The casing I0 is provided with a longitudinal slot 20, in a position tobe bisected by a plane radial to the casing Ill and the slot extendsentirely through the wall of the casing and throughout the lengththereof. The end plate I4 is slotted at 2| in conformity with the slot20 which latter is closed at its opposite end by the end plate l5.

The roller l2 may be of wood or other desire material and thecylindrical surface thereof is suitably coated to provide an efficientblade edge sharpening surface. I

This abrading coating indicated at C is preferably provided by renderingthe surface of the roller adhesive as by coating same with glue andthereafter rolling it in an abrasive material such as emery powderwhereby a highly efficient grinding surface 'is provided.

The slot 20 is relatively wide and in the sharpening operation the bladeB of a shears or scissors S is placed longitudinally therein asindicated in Figure 6 with the bevelled edge in contact with theabrading roller I2, and due to the width of the slot the blade is cantedas illustrated by dotted lines in Figure 4 and in this position theblade is firmly held by a hand of the operator whereby the bevel willuniformly} contact the roller l2 throughout the length of the blade. Theslot 21 in the plate l4 admits the blade and the other end plateprevents engagement of the hand with the end of a long blade which mayotherwise occur when rotating the roller through the crank l6.

With the blade in the position shown in Figure 6 which may be firmlyheld together with the casing I!) in the left hand, and handle I! isgrasped by fingers of the right hand and the roller I2 rotated atrelatively high speed where- 'upon the edge of the blade B is rapidlyand efficiently sharpened with a uniform bevel. The other blade of theshears S may then be inserted in the slot and be likewise sharpened.

When the abrading coating on the roller l2 becomes ineffective the platel5 may be quickly removed, the roller I2 withdrawn, and a new abrasivecoating applied thereto.

It should readily be appreciated from the foregoing disclosure that theinvention provides a 'novel sharpener whereby the blades of shears,

scissors and the like may be quickly and accurately sharpened without inany way subjecting the operator to danger of being cut by an exposededge being sharpened.

While I have disclosed but a single specific embodiment of my invention,such is to be considered as illustrative only, and not restrictive, thescope of the invention being defined in the sub-joined claims.

What I claim, and desire to secure by United States Letters Patent is:

1. A device for sharpening the blades of shears, scissors, and the like,comprising an elongated tubular casing, a centrally apertured platedetachably secured to each end of the casing, a spindle extendingaxially through the casing and rotatably supported in said apertures, amanipulating crank on one end of the spindle, an abrading roller securedto the spindle and a slot extending through the wall of the casing andthroughout the length thereof, the plate at the end of the casingadjacent the crank closing the adjacent end of the slot, and the otherplate having a slot alined with the slot in the casing for receiving ashears blade its full length within the casing slot and with its edge inbearing contact with the roller.

2. The structure defined in claim 1 wherein the slot in the casing isradially disposed in transverse section of the casing and is ofsubstantial width for positioning the blade nonradial to-the casing forproper and uniform bevelon the edge being sharpened.

3. A blade sharpening device comprising an elongated casing having abore extending longitudinally therethrough, an abrading roller rotatablein the bore, a longitudinal slot extending through the wall of thecasing and opening through both ends thereof, and plates secured to theopposite ends of the casing, one of the plates having a slot conformingto the adjacent end of the slot in the casing to admit a blade, with itsedge in contact with the abrading roller, and the other plate closingthe other end of the casing slot, said roller being supported by anaxial spindle, said plates being centrally apertured for freelyreceiving the spindle, and a crank on one end of the spindle.

4. A blade sharpening device comprising an elongated casing havingarbore extending longitudinally therethrough, an abrading roller r0-tatabl-e in the bore, a longitudinal slot extending through the Wall ofthe casing and opening through both ends thereof, and plates secured tothe opposite ends of the casing, one of the plates having a slotconforming to the adjacent end'of the slot in the casing to admit ablade, with its edge in contact with the abrading roller, and the-otherplate closing the other end of the casing slot, said plate'beingremovably secured to the casing for expeditious removal and re- ARTHURB. MAWLE.

